Study: Moon phase affects length of stay, mortality

Patients who need to undergo acute aortic dissection might want to schedule their surgery around the moon, according to a recent study at Rhode Island Hospital. Acute aortic dissection repair performed in the waning full moon appears to reduce the odds of death, and a full moon was associated with shorter length of stay, the findings showed.

The study was published July 9 on the website of the journal Interactive Cardiovascular and Thoracic Surgery. Its purpose was to assess the effects of natural time variations of the season and the lunar cycle phase on hospital survival and length of stay after acute aortic dissection repair.

"While there has been previous research of seasonal impacts on cardiovascular disease, there has not been any data about the effect of the lunar cycles on cardiac cases, until now," senior author Frank Sellke, MD, chief of cardiothoracic surgery and co-director of the Cardiovascular Institute at Rhode Island, The Miriam and Newport hospitals, said in a news release. "We focused the study on patients having aortic dissection and found that the odds of dying following this procedure were greatly reduced during the waning full moon, and that length of stay was also reduced during the full moon."

Researchers studied the relationship of lunar cycles and seasonal variation on 210 surgical patients from January 1996 through December 2011, the article states. Patients were divided into two surgical groups: Group A consisted of 109 patients having repair of ascending aortic dissection, and Group B was 101 patients having aortic dissection and either aortic valve surgery, coronary bypass surgery or both. "The odds of dying in the full-moon cycle versus the new moon cycle was significantly reduced" for both groups, the authors wrote. The researchers also examined whether the lunar cycle had any effects on patientsí lengths of stay.

According to the findings, patients who had aortic dissection performed during the full-moon phase had significantly shorter lengths of stay than two other moon phases — 10 days for the full-moon cycle compared with 14 days for the other phases. Patients in Group A also had a slightly longer average length of stay when compared with patients in Group B.

"Can we always plan for such procedures to be performed around lunar cycles? Of course not," Sellke said in the release. "But better understanding the effects of the environment — including seasonal and lunar cycles — on our health can help us to better understand these rhythms, and ultimately provide better care for our patients."

The authors wrote that more research is needed, but possible causes "may be related to the influence of gravitational forces exerted by the moon on the earth and earth organisms, including the human body, with consequent changes in human behavior during the lunar cycle, possibly influenced by gratitational forces acting on the neuroaxial system as well as other unknown factors." In a previous study of 1,437 cases, the number of cardiovascular emergencies presenting to the ED was linked to the lunar phase, with more deaths occuring during the first and last lunar quarters. Data from 1999-2001 has shown an increased incidence of acute cardiac events during the new moon phase.